Indicating instrument.



PATBNTED AUG. 23, 1904. I

W. B. POTTER. INDIGATING INSTRUMENT.

. APPLICATION FILED NOV. 25, 1898.

NO MODEL.

WITNESSES Wm j aw.-

UNITED STATES Patented August 23, 1904.

PATENT QEEICE.

WILLIAM B. POTTER, or SCHENECTADY, NEW YORK, ASSIGNOR To THE GENERAL ELEoTEIO COMPANY, A CORPORATION OF NEW YORK.

INQDICATING INSTRUIIVIENT.

SPECIFICATION forming part of Letters Patent No. 768,343, dated. August 23, 1904. Application filed November 26, 1898. Serial No, 697,329. (No model.)

To all whom it may concern;

Be it known that I, WILLIAM'B. POT ER, a

' citizen of the United States, residing at Schenectady, county of Schenectady, in-the State. of New York, have invented certain new and rate form of such an instrument which may be I soarranged as to act, for example, as a checkupon a motorman in the operation of electric cars or trains. It may happen, for instance, that a given current would be unsafe under special conditions, and yet circumstances might justify taking the risk of injury to the apparatus by employing this current for a certain time. This could not be provided for'by the ordinary overload circuit-breaker or by fuses. It may also happen that while the protection of the circuit-breaker may be present it*may be set designedly for current at which it would be unsafe to operate for anylength of time, while a lower current 'would be undesirable and if employed at all should be used with caution. In such cases a superintendent or other ofiicer may by my invention be provided with the means of ascertaining when and how often a dangerous current has been permitted to flow in any given circuit.

I shall describe the invention with reference to its use in electric railways, because that is where it has its most extended application; but the results and methods of application would be the same wherever the device might be employed.

In brief, the apparatus embodying my invention would generally be as follows: A series coil of the usual construction designed to .carry the largest current that may be employed in the circuit is provided with one or more armatures, each held away from the coil by suitable springs. The arrangement is such that the circuit is not opened by the arma'ture, as in the ordinary circuit-breaker,

but'lnstead a consecutive register or other indicator is actuated by the armature, so that each time the predetermined current is exceeded the register will be actuated. -In practice the instrument is inclosed in a case and is arranged so that it may be readily inspected from time to time, but cannot be tampered with by unauthorized persons.

The accompanying drawings show a convenient embodiment of the invention in the form of an indicating-ammeter provided with three difierent armatures for actuating as many diflierent registers.

In the drawings, Figure 1 is a front elevation of the construction. Fig. 2'is a side elevation, and Fig. 3 a rear elevation, while Fig.

4 is a diagram of the circuits. -A is the frame of the apparatus to which the registers B B B are attached, each being connected by a rod Z2 6 b with one of the armatures F F F These latter pull against the springs C O Ciprovided with adjusting-nuts.

The coil E, with terminals E E, is an ordinary series coil and may have a core E although this may be omitted, if desired. Insulation I of course separates the magnetic circuit of the apparatus from the current-carrying portions.

In Fig.' 4 the circuit is shown, the construction A being included in series with the motors M M between the trolley and ground.

The operation of the device is as follows: Assume, for instance, that the spring C is set for five hundred amperes, the spring C for Six hundred, and C for seven hundred. Each time that a current of five hundred amperes passes through the series coil E the armature F will be drawn down, operating the register B. When the current exceeds six hundred amperes, the armature F will also be drawn down, but necessarily F will also be actuated, and similarly when seven hundred amperes is exceeded all three of the armatures will be drawn down. shown are 531, 41, and 2, showing that the current seven hundred amperes has been exceeded twice,while current between six hundred and seven hundred amperes has been taken forty-one minus two or thirty-nine times, and current between five hundred and The readings six hundred .amperes five hundred and thirtyone minus forty-one, or four hundred and ninety times.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination with a coil, of a plurality of magnetic parts movable thereby, one part being inoperative until a predetermined current passes through the coil and the others being inoperative until the passage of successively-higher predetermined currents through said coil, and a register for each part adapted to be operated thereby.

2. The combination with a coil, of a plurality of magnetic members therefor, means for adjusting each of said members so that it is not operated by normal currents flowing through said coil and cannot be operated until a predetermined current flows through the latter, and registering devices each of which is connected with its corresponding magnetic member so that it is operated when said magnetic member is operated.

8. The combination with an electric motor the current through which is required to be varied frequently between wide limits at the will of the operator in order to drive a load connected thereto, of registering mechanism, and electromagnetic means for operating said mechanism which is actuated automatically only when a predetermined'maximum current flows through said motor.

L. The combination with a pair of railwayrnotors the current through which is required to be varied frequently between wide limits at the will of the motorman in order to drive a load connected thereto, of a coil in series with said motors, an armature set to be attracted to the coil by current at and above a certain amperage only, and a registering device actuated by said armature.

5. The combination with a translating device through which in case of emergency a current liable to prove injurious may be caused to flow, of normally inoperative means actuated only when the current through said translating device rises above a predetermined abnormal limit to indicate that said limit has been exceeded and to register the number of times it occurs.

6. The combination with an electric vehiclemotor, of a coil connected in circuit with Said motor, and a registering device constructed and arranged to be actuated by said coil and to register the number of times a current of predetermined abnormal amperage flows through the motor.

7. In combination, a circuit in which an electrical machine is located, a coil in the circuit in series with said machine, a magnet member actuated thereby, means for preventing the actuation of said member while the current in said circuit remains below a predetermined abnormal value, and a registering device which is actuated by the movement of said magnet member to indicate the number of times a current of predetermined abnormal value flows through said circuit.

8. The combination with a translating device, of means for indicating when a predetermined current passes through said translating device, independent means for indicating when a greater predeterminml current passes through said translating device, and means for operating said indicating means at the proper times.

9. The combination with a translating device, of means for indicating when a predetermined current passes through said translating device, independent means for indicating when a greater predetermined current passes through said translating device, and a single coil connected in circuit with said translating device for actuating said indicating means.

10. In combination, a translating device in an electric circuit, a register to indicate when a predetermined current in said translating device is exceeded, a second register to indicate when a greater predetermined current has been exceeded, said first-named register operating when the second register operates, a third register to indicate when a still greater predetermined current is exceeded, said lirst and second registers operating when the third operates, and means for actuating said registers.

In testimony whereof I have hereunto set my hand this 22d day of November, 1898.

WILLIAM B. POT'll llt.

Witnesses:

B. B. HULL, EDw. VVILLIAMS, Jr. 

